Comments:

Ah yes, literally the only in combat healing build that actually lets you heal effectively in combat. At least from Paizo classes. I still wish there was a cleric and paladin archetype that really delved into healing that wasn't 3rd party. I know some players who would love the idea (myself included) and we're all kind of stuck with an Oracle or a refluffed Vitalist of some kind if a DM is kind enough to allow it.

Merciful Healer clerics are quite good. At 6th level their cure spells are empowered for free. Plus, although channel energy heals less to an individual target, it's not that much less and if your whole group is injured can be quite a bit, especially if you add the utility of mercies on top of it.

Quite good isn't good enough. Unless you heal as much damage as the party takes and can do it for multiple battles, they can't be only an in combat healer.

Life Oracles do one better, giving other people a bit of DR to take damage themselves. (Which they can heal quickly.)

A real healing cleric would only get restorative spells, reach spells on healing automatically, and bonuses to all healing, including their channel positive energy equal to their wisdom. Oh, and the ability to have overheal become temp hit points.

The vitalist works by having absolute control of every hit point they heal and the ability to heal a loooot of it.

If he took the opening himself, at least to some degree it qualifies as his choice. Can have a door wide open and not necessarily take it. Might not be as efficient or effective but still one's choice to take the path.